Conventionally known is a railcar air conditioner to which outside air is introduced, through a vent hole by a ventilation fan and to which air in a room is introduced through a vent hole by a fan (PTL 1). According to the an conditioner described in PTL 1, the air introduced through the vent hole is cooled by an evaporator or heated by a heater to be supplied to a room through an air outlet. The vent hole through which the air in the room is introduced is formed on a ceiling of the room, and an internal structure of the air conditioner can be seen through the vent hole, so that a visual quality is poor. In addition, since the internal structure is visible, it is handled carelessly, and internal devices may be damaged.